Determine the distance between two ellipses (in 3D)

Determine the minimum distance (and corresponding angles) between two ellipses
1.1K descargas
Actualizado 2 May 2020

The problem of finding the geometric (minimum) distance between two arbitrary ellipses is surprisingly difficult. The general problem of finding all stationary points (minimum/maximum/saddle, no less than 12 possible points) has indeed been solved, but that algorithm is horrificly complex and would require thousands if not millions of operations once implemented.
The function distanceEllipseEllipse() is based on a somewhat more practical algorithm which limits itself to minima in the distance function. It is based on repeatedly finding the distance between a point and an ellipse, which can be done analytically (see my other post, distanceEllipsePoints.m). The algorithm by itself is not very robust (it frequently finds a local minimum, which is *not* the true distance).
This function executes the algorithm 4 times, for 4 different initial values, which greatly improves its robustness. Some numerical experimentation (comparing with a brute-force search) has shown that the true minimum distance is returned in more than 95% of the cases. The algorithm is implemented such that MATLAB's JIT-accelerator can accelerate it to the fullest extent, which makes it pretty fast and well-suited to handle large datasets requiring this calculation.
This is an implementation of the algorithm described in
Ik-Sung Kim: "An algorithm for finding the distance between two
% ellipses". Commun. Korean Math. Soc. 21 (2006), No.3, pp.559-567.

A copy-pastable example (also in header of M-file):

% Ellipse1 Ellipse2(=circle)
a = [2.0 1.0];
b = [0.5 1.0];
c = {[0,0,0], [-2,2,0]}; % location of centers
u = {[1,0,0], [1,0,0]}; % both oriented in XY-plane
v = {[0,1,0], [0,1,0]}; % to visualize them more easily

% plot the ellipses
f = 0:0.01:2*pi;
E1 = [a(1)*cos(f) + c{1}(1); b(1)*sin(f) + c{1}(2)];
E2 = [a(2)*cos(f) + c{2}(1); b(2)*sin(f) + c{2}(2)];
figure, hold on
plot(E1(1,:),E1(2,:),'r', E2(1,:),E2(2,:),'b')
axis equal

% run routine
[min_dist, fp_min, fs_min] = ...
distanceEllipseEllipse(a,b,c,u,v)

% plot the minimum distance returned
x = [a(1)*cos(fp_min) + c{1}(1), a(2)*cos(fs_min) + c{2}(1)];
y = [b(1)*sin(fp_min) + c{1}(2), b(2)*sin(fs_min) + c{2}(2)];
line(x,y,'color', 'k')

This should generate the screen shot given here.

Citar como

Rody Oldenhuis (2024). Determine the distance between two ellipses (in 3D) (https://github.com/rodyo/FEX-distanceEllipseEllipse/releases/tag/v1.3), GitHub. Recuperado .

Compatibilidad con la versión de MATLAB
Se creó con R2009b
Compatible con cualquier versión
Compatibilidad con las plataformas
Windows macOS Linux
Categorías
Más información sobre Geometric Transformation and Image Registration en Help Center y MATLAB Answers.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

No se pueden descargar versiones que utilicen la rama predeterminada de GitHub

Versión Publicado Notas de la versión
1.3

See release notes for this release on GitHub: https://github.com/rodyo/FEX-distanceEllipseEllipse/releases/tag/v1.3

1.2.0.0

[linked to Github]
Description update

1.1.0.0

Updated contact info

1.0.0.0

Para consultar o notificar algún problema sobre este complemento de GitHub, visite el repositorio de GitHub.
Para consultar o notificar algún problema sobre este complemento de GitHub, visite el repositorio de GitHub.